ABSTRACT Climate action threatens to exacerbate existing social inequities, so it is important for justice to be at the heart of national responses to climate change. Based on an understanding of climate change as a manifestation of severed relationships and exploitative dynamics that are produced and reproduced through colonial, capitalist, patriarchal systems, we argue that the ways in which we conceptualize and enact climate justice must be decolonial, ecocentric, relational and integrative. Consistent with this positioning, we sought to develop an Indigenous climate justice policy analysis tool to assess and inform policy development. We drew on elements of existing frameworks and tools to develop a tool, which was progressively refined following external advisory group review and piloting. The tool addresses five dimensions of justice (relational, procedural, distributive, recognition and restorative), each of which comprises individual criteria assessed according to three levels of achievement. This rating system acknowledges progress within existing social, political and economic systems, but also identifies system transformation as a prerequisite for achieving genuine justice. Application of the tool focuses attention on issues well beyond typical climate policy considerations, such as the capacity of all human and non-human entities to express political agency. The tool has been developed for use in analysing national climate policy in Aotearoa New Zealand, but we have endeavoured to make it adaptable for use in other settings.